1. Field of the Invention
The present invention relates to an adapter apparatus which distributes media data recorded on a disk recording medium of an image sensing apparatus to a data receiving terminal on a network and a control method thereof, and a computer program.
2. Description of the Related Art
In recent years, in the field of digital video cameras, those which record moving and still images using optical disks such as DVDs and the like as recording media (to be referred to as disk recording media hereinafter) in place of tapes have become mainstream. When a DVD is used as a disk recording medium, the DVD-Video format which has high compatibility to general DVD players is available as the recording format. As another recording format, for example, the DVD-VR format which allows easy editing of recorded images is known, although some general DVD player models cannot play back this format. The user selectively uses these recording formats depending upon application purposes.
Recently, a technical specification called DLNA has been established so as to connect digital AV apparatuses and personal computers to each other and to use data of moving images, music, and still images in a home network. Note that “DLNA” is an abbreviation for Digital Living Network Alliance.
In the DLNA guideline, a server for providing contents is called a DMS (digital media server), and a client that plays back contents is called a DMP (digital media player). The DLNA guideline specifies the connection conditions of these apparatuses. The apparatuses compatible to this DLNA guideline can be connected to each other by merely connecting a cable without any special settings, and can share their contents (moving image, music, still image files, and the like).
For example, when a camera such as a digital camera, DVD video camera, or the like is connected to a camera adapter with a DMS function, contents recorded on a recording medium of that camera are accessed via a LAN, and a network media player as a DMP plays back these contents. In this case, in order to distribute media data (moving or still image files or the like) on a disk recording medium via the LAN, the media data recorded on the disk recording medium needs to be accessible by the network media player.
In order to set the media data in an accessible state, the media data needs to be converted into a data sequence that can be played back by a general DVD player, and then to a UDF file system format as a data sequence compatible to a DVD-ROM as a read-only medium. Such series of processes are called finalize processing (for example, Japanese Patent Laid-Open No. 2004-22043). Nowadays, most apparatuses which handle optical disks maintain compatibility by executing this finalize processing.
FIG. 7 shows a data sequence in the DVD-Video format.
An optical disk is divided, from the head of its inner side, into a PMA (Programmable Memory Area), lead-in, data area, and lead-out. Moving image files and the like are recorded in the data area. The data area is divided, from the lead-in side, a UDF-Bridge file system (to be referred to as UDF) area, VMG (Video Manager) area (disk control information), and video data recording area.
The UDF and VMG areas are control information recording areas for managing files including video data recorded on an optical disk. The VMG area is an area that records information for a DVD player, and records control information used to manage whole video data recorded on the video data recording area. The UDF area records control information used to manage whole video data recorded in the video data recording area in a format compatible to a file system of an information apparatus (such as a personal computer (PC) or the like).
The video data recording area is a program area for recording actual video data, and uses a VTS (Video Title Set) as a unit to record video data including a plurality of VTS#1 to VTS#n. One VTS includes, from the head position, VTSI, a VTSM_VOBS, a VTSTT_VOBS, and a VTSI_BUP.
Note that the VTSI is an abbreviation for Video Title Set Information, and the VTSM_VOBS is an abbreviation for a Video Object Set for VTSM. Also, the VTSTT_VOBS is an abbreviation for Video Object Set for Titles in VTS, and the VTSI_BUP is an abbreviation for a Backup of VTSI.
The VTSI records recording position information or the like, which is title management information required to play back video data, and information required to manage video data. The VTSM_VOBS records title menus of video data. The VTSTT_VOBS records moving image files in the MPEG2PS format as real data of video data. The VTSI_BUP is backup information of the VTSI.
When an information apparatus such as a PC or the like accesses an optical disk recorded using such format, it can search for required files with reference to the UDF area and can play back that disk. On the other hand, when a DVD player accesses that optical disk, it can search for required files with reference to the VMG area, and can play back those files.
However, as described above, when a moving or still image file sensed by a DVD video camera is to be played back by the network media player via a home LAN, the sensed moving or still image file does not undergo the finalize processing. For this reason, the network media player cannot access the moving or still image file recorded on a DVD disk of the DVD video camera.
In order to execute the finalize processing, target data needs to be converted into a data sequence that can be played back by a general DVD player, and also into the UDF file system format as a data sequence compatible to a DVD-ROM as a read-only medium. In order to maintain full compatibility, even when the amount of recording data is small, dummy data up to about 1 GB needs to be recorded on a DVD disk, and this requires a considerably long processing time. Furthermore, in order to additionally record data on an optical disk on which data has already been recorded, processing for canceling the finalize process is required, resulting in troublesome operations.
When a write-once disk recording medium such as a DVD-R or the like is used as an optical disk used in recording, if that disk recording medium undergoes the finalize processing, additional recording cannot be made if that medium has a large remaining recording capacity.